1. Field of the Invention
This invention relates generally to the testing of storage batteries, and more particularly, to a new and improved method and apparatus for testing the condition of batteries used with internal combustion automobiles wherein the condition of the battery and the related circuitry is measured each time the engine of the automobile is started. The invention is specifically concerned with the novel method and apparatus whereby the cranking motor of the internal combustion engine furnishes the load for the battery, and an electronic apparatus automatically measures the condition of the battery and the related circuitry each time the engine is started.
2. Description of the Prior Art
Throughout the many prior years of the use of electrical starting of internal combustion automobiles, the condition of the automobile storage battery has been of a major concern to the motorist. Heretofore, several methods have been used to determine the charge and condition of such a battery when under a large current load. This prior art method is usually accomplished by a device that is attached to the positive and negative terminals of the battery, in or out of the automobile. Said device furnishes a low resistance path between these terminals and contains a simple voltmeter circuit with a meter face that is calibrated in regions of bad, questionable, and good, by means of a printed decal.
The prior art testing methods have consistently utilized concepts of off-line analysis for automotive battery testing applications. The battery is tested in the car or removed from it. In either case, an external load is applied and the voltage measurements are made on a calibrated meter face, by light displays, or other means. The test is usually performed as part of a diagnostic procedure initiated because of failure of some part of the engine or electrical system components.
Other examples of prior art battery testers which compare loaded to non-loaded voltage levels are disclosed in U.S. Pat. Nos. 3,356,936; 3,899,732; 4,027,231; 4,028,616; 4,044,304; 4,080,560; 4,180,770 and 4,193,025.